African University of Science and Technology: Recent submissions

Now showing items 321-340 of 4824

  • On Villani's conjecture concerning entropy production for the Kac Master equation 

    Einav, Amit (America Institute of Mathematical SciencesKinetic and Related Models, 2011-06-01)
    In this paper we take an idea presented in recent paper by Carlen, Carvalho, Le Roux, Loss, and Villani ([3]) and push it one step forward to find an exact estimation on the entropy production. The new estimation essentially ...

  • Sharp trace inequalities for fractional Laplacians 

    Einav, Amit; Loss, Michael (American Mathematical SocietyProceedings of the American Mathematical Society, 2012-04-05)
    The sharp trace inequality of José Escobar is extended to traces for the fractional Laplacian on Rⁿ and a complete characterization of cases of equality is discussed. The proof proceeds via Fourier transform and uses Lieb’s ...

  • Deformations of Cayley submanifolds 

    Ohst, Matthias (University of CambridgeDepartment of Pure Mathematics and Mathematical StatisticsTrinity College, 2016-03-01)
    Cayley submanifolds of R^8 were introduced by Harvey and Lawson as an instance of calibrated submanifolds, extending the volume-minimising properties of complex submanifolds in Kähler manifolds. More generally, Cayley ...

  • Level-raising and symmetric power functoriality, III 

    Clozel, Laurent; Thorne, Jack Arfon (Duke University PressDuke Mathematical Journal, 2016-12-09)
    The simplest case of the Langlands functoriality principle asserts the existence of the symmetric powers Symn of a cuspidal representation of GL.2/ over the adèles of F , where F is a number field. In 1978, Gelbart and ...

  • A 2-adic automorphy lifting theorem for unitary groups over CM fields 

    Thorne, Jack Arfon (SpringerMathematische Zeitschrift, 2016)
    We prove a ‘minimal’ type automorphy lifting theorem for 2-adic Galois representations of unitary type, over imaginary CM fields. We use this to improve an automorphy lifting theorem of Kisin for GL_2.

  • Harmonic Discs of Solutions to the Complex Homogeneous Monge-Ampere Equation 

    Ross, Julius Andrew; Nystrom, David Witt (SpringerPublications mathématiques de l'IHÉS, 2015-05-30)
    We study regularity properties of solutions to the Dirichlet problem for the complex Homogeneous Monge-Ampere equation. We show that for certain boundary data on P^1 the solution Φ to this Dirichlet problem is connected ...

  • Polynomials and models of type theory 

    von Glehn, Tamara (University of CambridgeDepartment of Pure Mathematics and Mathematical StatisticsMagdalene College, 2015-06-30)
    This thesis studies the structure of categories of polynomials, the diagrams that represent polynomial functors. Specifically, we construct new models of intensional dependent type theory based on these categories. Firstly, ...

  • Variation of Gieseker moduli spaces via quiver GIT 

    Greb, Daniel; Ross, Julius Andrew; Toma, Matei (Mathematical Sciences PublishersGeometry & Topology, 2016)
    We introduce a notion of stability for sheaves with respect to several polarisations that generalises the usual notion of Gieseker-stability. We prove, under a boundedness assumption, which we show to hold on threefolds ...

  • Potential automorphy and the Leopoldt conjecture 

    Khare, Chandrashekhar; Thorne, Jack Arfon (Johns Hopkins University PressAmerican Journal of Mathematics, 2017-10-01)
    We study in this paper Hida's p-adic Hecke algebra for GL_n over a CM field F. Hida has made a conjecture about the dimension of these Hecke algebras, which he calls the non-abelian Leopoldt conjecture, and shown that his ...

  • Quantifying separability in virtually special groups 

    Hagen, Mark Fearghus; Patel, Priyam (Mathematical Society PublishingPacific Journal of Mathematics, 2016)
    We give a new, effective proof of the separability of cubically convex-cocompact subgroups of special groups. As a consequence, we show that if G is a virtually compact special hyperbolic group, and Q ≤ G is a K-quasiconvex ...

  • Cubulating hyperbolic free-by-cyclic groups: the irreducible case 

    Hagen, Mark Fearghus; Wise, Daniel T (Duke University PressDuke Mathematical Journal, 2016)
    Let V be a fi nite graph and let ∅ : V → V be an irreducible train track map whose mapping torus has word-hyperbolic fundamental group G. Then G acts freely and cocompactly on a CAT(0) cube complex. Hence, if F is a ...

  • The 1-2 model 

    Grimmett, Geoffrey Richard; Li, Zhongyang (American Mathematical SocietyIn the Tradition of Ahlfors–Bers, VII, 2017)
    The current paper is a short review of rigorous results for the 1-2 model. The 1-2 model on the hexagonal lattice is a model of statistical mechanics in which each vertex is constrained to have degree either 1 or 2. It was ...


  • Detecting and Localizing Differences in Functional Time Series Dynamics: A Case Study in Molecular Biophysics 

    Tavakoli, Shahin; Panaretos, Victor M (Taylor & FrancisJournal of the American Statistical Association, 2016-03-22)
    Motivated by the problem of inferring the molecular dynamics of DNA in solution, and linking them with its base-pair composition, we consider the problem of comparing the dynamics of functional time series (FTS), and of ...

  • Free groups and the axiom of choice 

    Kleppmann, Philipp (University of CambridgeDepartment of Pure Mathematics and Mathematical Statistics, 2016-01-05)
    The Nielsen–Schreier theorem states that subgroups of free groups are free. As all of its proofs use the Axiom of Choice, it is natural to ask whether the theorem is equivalent to the Axiom of Choice. Other questions arise ...

  • Effectivity of Iitaka fibrations and pluricanonical systems of polarized pairs 

    Birkar, Caucher; Zhang, De-Qi (SpringerPublications mathématiques de l'IHÉS, 2016-01-18)
    For every smooth complex projective variety W of dimension d and nonnegative Kodaira dimension, we show the existence of a universal constant m depending only on d and two natural invariants of the very general fibres of ...

  • Proof of a conjecture of Batyrev and Nill 

    Favero, David; Kelly, Tyler Lee (Johns Hopkins University PressAmerican Journal of Mathematics, 2016)
    We prove equivalences of derived categories for the various mirrors in the Batyrev-Borisov construction. In particular, we obtain a positive answer to a conjecture of Batyrev and Nill. The proof involves passing to an ...

  • Kriging prediction for manifold-valued random fields 

    Pigoli, Davide; Menafoglio, Alessandra; Secchi, Piercesare (ElsevierJournal of Multivariate Analysis, 2015-12-25)
    The statistical analysis of data belonging to Riemannian manifolds is becoming increasingly important in many applications, such as shape analysis, diffusion tensor imaging and the analysis of covariance matrices. In many ...

  • Turán-type results for complete h-partite graphs in comparability and incomparability graphs 

    Tomon, István (SpringerOrder, 2015-01-05)
    We consider an h-partite version of Dilworth's theorem with multiple partial orders. Let P be a fi nite set, and let <₁, ..., <ᵣ be partial orders on P. Let G(P, <₁, ..., <ᵣ) be the graph whose vertices are the elements ...

  • Problems in Ramsey theory, probabilistic combinatorics and extremal graph theory 

    Narayanan, Bhargav (University of CambridgeDepartment of Pure Mathematics and Mathematical Statistics, 2015-11-10)
    In this dissertation, we treat several problems in Ramsey theory, probabilistic combinatorics and extremal graph theory.